Embodiments relate to radiometers and, more importantly, to a dynamic multi-mode radiometer system and method for automated calibration of the system.
A radiometer includes a high performance radio frequency (RF) receiver that translates passive millimeter wave energy into a voltage (Vout) proportional to the received RF power (Pin). As the data received by the radiometer is collected a time varying response is compiled and converted into a grey-scale video. A radiometer may be configured with multiple radiometer channels each with an RF receiver. The multiple radiometer channels can be arranged in a parallel array perpendicular to the direction of flight. Thus, a completely passive “push broom” image can be compiled into a map detailing physical features along a surface of interest (typically a geological surface).
Generally, each channel of a radiometer is calibrated by means of a reference based calibration so that the resolutions of the relative differences in the images are attainable to produce the map detail. To achieve suitable resolution of the image from the radiometer, known temperature references have to be presented to the receiver input for proper characterization and calibration with an externally presented load.